The present invention relates to a pneumatic transmission apparatus for carrying materials such as small resin molds, metal parts or powdered material.
Two basic types of transmission apparatus for carrying materials such as resin molds, metal parts, or powdered material, are known in the prior art. These are a pressurized air introduction type and air suction type.
In the former apparatus, a pressurized air supply is connected to an inlet of a tubular transmission passage. A flow of air produced within the tubular transmission passage by the pressurized air supply, carries materials from the inlet through the transmission passage to an outlet.
The latter apparatus has an overall structure similar to the former. An air suction means is connected to the outlet of the tubular transmission passage. The applied suction produces a flow of air within the tubular transmission passage, which carries materials from the inlet through the passage to the outlet.
In both types of device, materials are transmitted by straight air flow in the tubular transmission passage. As a consequence, stalled air flow may occur within the transmission passage. The transmission distance is limited, since long distance transmission increases the likelihood of stalled flow. In addition, regulation of travel speed is difficult and the prior art apparatus is not suitable for low speed transmission of materials.
When the tubular transmission passage contains a corner or sharp bend, parts being transmitted may collide with each other, or impact or rub against inner surface of the tubular transmission passage, thereby causing damage to the parts, and wear of the tubular transmission passage. Therefore, the prior art apparatus is not suitable for transmission of fragile materials which would be damaged by even minor impact.